| Date | Value |
|---|---|
| Mar 4, 2017 08:55 | 1470 ppm |
| Feb 27, 2017 04:26 | 1440 ppm |
| Feb 18, 2017 04:36 | 1470 ppm |
| Feb 7, 2017 12:35 | 1350 ppm |
| Feb 3, 2017 04:15 | 1425 ppm |
| Jan 30, 2017 04:48 | 1380 ppm |
| Jan 26, 2017 06:43 | 1350 ppm |
| Jan 23, 2017 12:19 | 1410 ppm |
| Jan 22, 2017 09:17 | 1350 ppm |
| Jan 20, 2017 11:10 | 1300 ppm |
| Jan 19, 2017 12:34 | 1320 ppm |
| Jan 18, 2017 10:24 | 1400 ppm |
| Jan 17, 2017 05:15 | 1350 ppm |
| Jan 16, 2017 11:12 | 1320 ppm |